I know and understand that it costs them extra resources to expose follower count on the users endpoint but I am pretty sure it is much better than having people make thousands of calls to follows api instead of hundreds to users endpoint.
In my use case and many other who signed the Uservoice link above, it is clear that We will be making 100 calls to follows endpoint instead of 1 request to users endpoint. This is going to cost Twitch more cycles/resources in the end imo.